3D LITHOGEOCHEMICAL FOOTPRINT OF THE MILLENNIUM- McARTHUR RIVER UNCONFORMITY-TYPE URANIUM

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3D LITHOGEOCHEMICAL FOOTPRINT OF THE MILLENNIUM- McARTHUR RIVER UNCONFORMITY-TYPE URANIUM

DEPOSITS, SASKATCHEWAN, CANADA

By

© Shannon Dee Guffey

A thesis submitted to the School of Graduate Studies

in partial fulfillment of the requirements for the degree of

Master of Science Department of Earth Sciences Memorial University of Newfoundland

May 2017

St. John’s Newfoundland and Labrador

i ABSTRACT

The Millennium and McArthur River unconformity-related uranium deposits in the

southeastern Athabasca Basin, Saskatchewan, are overlain by hydrothermally altered

sandstones of the Manitou Falls Formation. The distal lithogeochemical footprints in these

sandstones, from unconformity to subcrop, are useful for vectoring toward mineralization

using simple major and trace element analyses. Large first order alteration envelopes are

defined by molar element ratios K/Al vs. Mg/Al, which surround smaller, second order

trace element haloes. At Millennium, median Mg/K molar ratios >0.2 define a 10-km

alteration envelope. Values increase significantly within 2 km of the deposit, coinciding

with Mo, Ga, and REE enrichment 100s of metres vertically above the deposit. At

McArthur River, K/Al <0.06 and Mg/Al <0.4 (molar), and elevated Ba, Sr, Ga, and Cs,

exhibit haloes 4–8 km along strike of the P2 trend, 100s of metres above the McArthur

River deposit.

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ACKNOWLEDGEMENTS

I have been fortunate during my Master’s degree to have had the support of many people. My utmost thanks go to Dr. Stephen J. Piercey, my advisor. His sense of humor and enthusiasm for research is infectious, making his students want to complete the best possible work. He helped design a project that perfectly fit my strengths in data analysis, but that also challenged me daily in every step of the scientific method, and I could not have asked for a better supervisor.

Drs. Kevin Ansdell (University of Saskatchewan) and Kurt Kyser (Queen’s University) have combined years of research experience in the world of unconformity- related uranium that was paramount in helping to bring my project to fruition, and they were always the first set of eyes on my work after Dr. Piercey. Gerard Zaluski and Tom Kotzer of Cameco Corporation were incredibly supportive. They reviewed and commented on the quarterly reports for the CMIC-Footprints project in addition to the chapters herein and the amount of time they spent personally on my work impressed me immensely, especially considering their responsibilities to their day jobs. I greatly appreciated their detailed and thoughtful responses to my inquiries, making the scientific discussions engaging and informative. Dave Quirt of AREVA Resources Canada was a tremendous help as well, whose tenacious attention to detail ensured that all information presented was as perfect and as cogent as it could be. Gerard, Tom, and Dave have spent the majority of their careers immersed in unconformity-related uranium deposits and their expertise has been invaluable.

Field work at the McArthur River site, funded in-kind by Cameco, was enormously benefitted by the assistance of Steve, Kevin, Kurt, Gerard, and Tom, who not only guided our work but lifted an impressive amount of core boxes. With me to collect samples and discuss our research objectives were Nicholas Joyce, Mary Devine, and Mohamed Gouiza, all members of the CMIC-Footprints project who made our time there enjoyable. Katelynn Brown, a summer student at Cameco, provided support as well and we thank Cameco for allowing us to utilize her.

My fellow members of the Piercey research group at Memorial University, past and present, have been welcome support. Dr. Jonathan Cloutier, Dr. Stefanie Lode, and Michael Buschette were especially helpful, as excellent editors of my writing drafts and through their tutelage in Target and Illustrator. My writing and figures improved as a direct result of their efforts; the time they spent to help me better my work and their friendship is very much appreciated. Dylan Goudie was a great help with the SEM analysis. Finally, I could not have returned to academia from the working world, and begin a new career at this stage in life, without the love and support of my husband, John Allen. I hope the arduous five- day journey he made with our cat, Buddy, was worth the suffering as my time here in St.

John’s would not have been as wonderful without them.

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Financial support was provided as part of the joint Natural Sciences and Engineering Research Council of Canada (NSERC) and Canadian Mining Innovation Council (CMIC) project “Integrated Multi-Parameter Footprints of Ore Systems: The Next Generation of Ore Deposit Models” through the NSERC Collaborative Research and Development Program, and by the NSERC-Altius Industrial Research Chair to Piercey, funded by NSERC, Altius Resources Inc. and the Research and Development Corporation of Newfoundland and Labrador.

TABLE OF CONTENTS

Abstract ……….i

Acknowledgements ………..ii

Table of Contents ………iii

List of Tables ………...vii

List of Figures ……….vii

List of Nomenclature and Abbreviations ……….…….x

List of Appendices ……….……..xi

Co-authorship Statement ……….………..….xiii

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Chapter 1: Introduction to the Millennium and McArthur River unconformity- related uranium deposits, Athabasca Basin, northern Saskatchewan, Canada

1.1 Introduction ... 1

1.2 Unconformity-related uranium deposits ... 4

1.3 Regional geology ... 7

1.3.1 Basement ... 7

1.3.2 Athabasca Basin ... 8

1.4 Deposit geology ... 10

1.4.1 Wollaston-Mudjatik Transition Zone (Hearne Province) ... 10

1.4.2 B1 and P2 trends ... 11

1.4.3 Manitou Falls Formation ... 12

1.5 Thesis objectives ... 14

1.6 Methods ... 16

1.6.1 Whole rock geochemistry: legacy database ... 16

1.6.2 Drill core sample collection: new data ... 17

1.6.3 Short-wave infrared spectroscopy ... 18

1.6.4 Results: 3D analysis and statistics ... 18

1.7 Presentation ... 19

References ... 19

Figures ... 28

Chapter 2: 3D geochemical footprint of the Millennium unconformity-type uranium deposit, Canada: implications for vectoring Abstract ... 33

2.1 Introduction ... 33

2.2 Regional geology ... 37

2.3 Deposit geology ... 39

2.3.1 Basement geology ... 39

2.3.2 Athabasca Group ... 40

2.3.3 Uranium mineralization ... 41

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2.3.4 Host-rock alteration ... 42

2.3.4.1 Basement alteration ... 43

2.3.4.2 Sandstone alteration ... 44

2.4 Lithogeochemistry ... 45

2.4.1 Analytical methods ... 45

2.4.2 Defining proximity to mineralization in sandstones ... 47

2.4.3 Statistical and spatial analysis ... 48

2.4.4 Results ... 49

2.4.4.1 Major elements ... 49

2.4.4.2 Trace element haloes ... 50

2.4.4.3 Lead isotope ratios ... 52

2.5 Discussion ... 53

2.5.1 Geochemical halo patterns ... 53

2.5.2 Implications for exploration ... 58

2.6 Conclusions ... 60

References ... 61

Figures ... 68

Chapter 3: The distal lithogeochemical footprint of the McArthur River unconformity-related uranium deposit: molar element ratios and trace element concentrations as district-scale vectors Abstract ... 84

3.1 Introduction ... 84

3.2 Regional geology ... 87

3.3 Deposit geology ... 90

3.3.1 Basement geology ... 90

3.3.2 Manitou Falls Formation ... 91

3.3.3 Alteration ... 92

3.3.3.1 Basement alteration ... 92

3.3.3.2 Manitou Falls Formation alteration ... 93

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3.3.4 Mineralization ... 94

3.4 Lithogeochemistry ... 95

3.4.1 Methods ... 95

3.4.2 Statistics ... 97

3.4.3 Proximity zones to mineralization ... 98

3.4.4 Results ... 100

3.4.4.1 Shortwave infrared spectroscopy ... 100

3.4.4.2 Major elements ... 100

3.4.4.3 Molar element ratios ... 101

3.4.4.4 Trace elements ... 102

3.4.4.5 Lead isotope ratios ... 103

3.5 Discussion ... 105

3.5.1 Quartz cementation and its effect on trace element distribution (restricted haloes) ... 105

3.5.2 Trace and major elements with correlations to both U and deposit location (broad haloes) ... 106

3.5.3 Clay alteration haloes and molar element ratios as a vectoring method (distal signature) ... 108

3.5.4 Implications for exploration ... 111

3.6 Conclusions ... 113

References ... 114

Figures ... 122

Chapter 4: Summary and Future Work 4.1 Introduction ... 137

4.2 Summary of key results ... 138

4.2.1 Shortwave infrared spectroscopy ... 139

4.2.2 Whole rock geochemistry: major elements ... 140

4.2.3 Whole rock geochemistry: molar element ratios ... 141

4.2.4 Whole rock geochemistry: trace elements ... 143

4.3 Discussion ... 145

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4.4 Conclusions ... 148

4.5 Future work ... 150

References ... 152

Figures ... 155

LIST OF TABLES Table 2.1: Geochemical halo dimensions of trace elements at the Millennium uranium deposit ……….………..…………83

Table 3.1: New data collected – McArthur River uranium deposit drill core ………... 136

Table A.1: Current element analysis suite for whole rock geochemistry, total and partial digestions, Saskatchewan Research Council Geoanalytical Laboratories ……….….… 166

Table B.1: Mean values of IR-active minerals at the Millennium study area …………. 179

Table B.2: Mean values of IR-active minerals at the McArthur River study area ……. 180

Table C.1: McArthur River deposit thin sections utilized for SEM analysis …….…… 188

LIST OF FIGURES Figure 1.1: Simplified geological map of the Athabasca Basin, Saskatchewan and Alberta, Canada ……….………. 28

Figure 1.2: Study areas of the Millennium and McArthur River uranium deposits ………...….... 29

Figure 1.3: Simplified genetic hydrothermal models for unconformity-related uranium deposits ……….……… 30

Figure 1.4: Typical cross section for the Millennium deposit………..………… 31

Figure 1.5: Typical cross section for the McArthur River deposit ………. 32

Figure 2.1: Simplified geological map of the Athabasca Basin, Saskatchewan and Alberta, Canada ………. 68

Figure 2.2: Typical cross section of the Millennium deposit: basement lithologies and

alteration ………... 69

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Figure 2.3: Millennium deposit study area: drill collars and proximity zones ………… 70 Figure 2.4: Simplified example of data analysis in spatial relation to the deposit location

……….…….. 71 Figure 2.5: Total clays present, and distribution of MgO with respect to deposit location ...… 72 Figure 2.6: Molar element ratio plots: K/Al vs. Mg/Al ………..…… 73 Figure 2.7: Molar ratios Mg/K with respect to deposit location ……...…………...….. 74 Figure 2.8: Typical spatial distribution patterns of select trace elements ……….……. 75 Figure 2.9: Spatial and statistical distribution of Mo: chimney-type pattern …….….... 76 Figure 2.10: Spatial and statistical distribution of HREE: hump-type pattern ……..…. 77 Figure 2.11: Spatial and statistical distribution of LREE: bullseye-type pattern …..….. 78 Figure 2.12: Silver, Bi, and Sb concentrations with respect to deposit location …...… 79 Figure 2.13: Lead isotope (

Pb/

Pb and

Pb/

Pb) ratios with respect to deposit location ………. 80 Figure 2.14: Plan view of study area with vectoring capabilities of whole-rock geochemistry……….….... 81 Figure 2.15: Longitudinal view of study area with vectoring capabilities of whole-rock geochemistry ……….……… 82 Figure 3.1: Simplified geological map of the Athabasca Basin, Saskatchewan and Alberta, Canada ……….……...….... 122 Figure 3.2: McArthur River study area: drill collar locations ……….……….… 123 Figure 3.3: Photo array of Manitou Falls Formation sandstones ….………... 124 Figure 3.4: Typical cross section of the McArthur River deposit: basement lithologies

………...…….….… 125 Figure 3.5: Cross sections of drill holes and samples collected for new data (2014) .. 126 Figure 3.6: Proximity zones for McArthur River study area ………….……..….…… 127 Figure 3.7: Short-wave infrared results in 3D ….………...….…. 128 Figure 3.8: Loss on ignition, P

O

, and MgO distribution with respect to deposit location

………. 129

Figure 3.9: Molar element ratio plots: K/Al vs. Mg/Al ……… 130

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Figure 3.10: Trace element haloes with a spatial relationship to elevated U .…..…… 131 Figure 3.11: Trace element haloes with a broad correlation to deposit location ….….. 132 Figure 3.12: Trace elements elevated with respect to DS-K trend …………..…..…… 133 Figure 3.13: Lead isotope distribution throughout the McArthur River study footprint

………... 134 Figure 3.14: Simplified graphic representation of the lithogeochemical footprint of the McArthur River deposit (longitudinal view) ………..……. 135 Figure 4.1: Simplified graphic representations of the lithogeochemical footprints of the Millennium and McArthur River deposits (longitudinal view) …..………. 155 Figure A.1: Instrument detection limit (e.g., Ag) capable of creating bias ………….. 164 Figure A.2: McArthur River legacy data: SPOT_S vs. COMP_S ……….... 164 Figure A.3: Instrument accuracy and precision variations over time (e.g., Ni) ….…... 165 Figure B.1: Mean values for infrared-active minerals at the Millennium and McArthur River uranium deposit study areas per lithofacies ……….. 176 Figure B.2: 3D view of infrared-active minerals at the Millennium uranium deposit study area ………. 177 Figure B.3: 3D view of infrared-active minerals at the McArthur River uranium deposit study area ………...………. 178 Figure C.1: Strontium and P

O

results at the McArthur River uranium deposit study area

………. 186 Figure C.2: Scanning electron microscopy image in backscattered electron mode of aluminum phosphate-sulfate (APS) minerals in thin section, from the McArthur River uranium deposit study area ……….…… 187 Figure C.3: Results of mineral liberation analysis for APS minerals per collection fence

……….… 188

Figure D.1: Drill core and sample locations from McArthur River uranium deposit study

area ………. 189

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LIST OF NOMENCLATURE AND ABBREVIATIONS AAS Atomic absorption spectrophotometry

APS Aluminum phosphate-sulfate mineral

B1 B1 conductive trend (Millennium study area)

COMP_S Whole rock geochemical samples selected as "composite sandstone"

(representative) from drill core, collected systematically

DS-K alkali-deficient dravite/sudoite to kaolin group trend (molar element ratio plots)

EDX Electron dispersive x-ray spectroscopy

HW Drill holes in hanging wall (true background) (McArthur River study area)

ICP-OES Inductively coupled plasma optical emission spectrometry ICP-MS Inductively coupled plasma mass spectrometry

I-DS illite to alkali-deficient dravite/sudoite trend (molar element ratio plots)

IDW Inverse distance weighting

K-I kaolin group to illite trend (molar element ratio plots)

LA-ICP-MS Laser ablation inductively coupled plasma mass spectrometry LOI Loss on ignition

M Drill holes in Main Zone (Millennium deposit) MFa Manitou Falls Formation A

MFb Manitou Falls Formation B MFc Manitou Falls Formation C MFd Manitou Falls Formation D MLA Mineral liberation analysis

N1 Drill holes in North 1 (Millennium study area) N2 Drill holes in North 2 (Millennium study area) N3 Drill holes in North 3 (Millennium study area) N4 Drill holes in North 4 (Millennium study area)

McA Drill holes surrounding McArthur River deposit, U content 0-5 ppm (McArthur River study area)

McA+ Drill holes surrounding McArthur River deposit, U content 0-10 ppm (McArthur River study area)

McA++ Drill holes in and surrounding McArthur River deposit, U content 0- 1000 ppm (McArthur River study area)

P Drill holes in Proximal Zone (Millennium deposit)

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P2 P2 conductive trend (McArthur River deposit); also drill holes in P2 trend (non-mineralized)

P2 Main Drill holes in P2 Main deposit (subeconomic) (McArthur River study area)

P2SW Drill holes in southwest end of P2 trend (background) (McArthur River study area)

S Drill holes in South Zone (Millennium study area) SEM Scanning electron microscopy

SPOT_S Whole rock geochemical samples selected as "spot sandstone"

(anomalous, or targeted feature) from drill core

SRC Saskatchewan Research Council Geoanalytical Laboratories SWIR Shortwave infrared spectroscopy

QA Quality assurance Q-Q Quantile-quantile plot THO Trans-Hudson Orogeny

UTM Universal Transverse Mercator URU Unconformity-related uranium WMTZ Wollaston-Mudjatik Transition Zone

LIST OF APPENDICES

Appendix A: Leveling and refinement of legacy whole rock geochemical results

from the Cameco archival database for use in this thesis

A.1 Introduction ………...…….……. 156

A.2 Data selection and refinement ……….………...…….… 156

A.2.1 Millennium and McArthur River …………...………...….……….……. 156

A.2.2 Millennium uranium deposit study area ……….…....….……. 160

A.2.3 McArthur River uranium deposit study area ………...….….…… 161

References ………... 163

Figures ……….……….….. 164

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Appendix B: Shortwave infrared spectroscopy (SWIR) of the Millennium and McArthur River uranium deposits: vectoring possibilities in the Athabasca Basin sandstones

B.1 Introduction ……….………. 167

B.2 Methods ……… 167

B.3 Results ……….….…… 168

B.3.1 Millennium deposit ………..…………...…....…….. 168

B.3.2 McArthur River deposit ………. 169

B.4 Discussion ……… 171

B.5 Conclusions ……….. 173

References ………...……..………. 174

Figures ……… 176

Appendix C: Preliminary investigation of aluminum phosphate-sulfate minerals with scanning electron microscopy C.1 Introduction ……….. 181

C.2 Methods ………..……….………. 182

C.3 Results .………..….…….. 182

C.4 Discussion ……...………. 183

C.5 Conclusions ……….………. 184

References ………...………... 185

Figures ………...………. 186

Appendix D: Samples collected at McArthur River deposit ……….. 189

Appendix E: Whole rock geochemistry: partial and total digestion results, from

samples collected in 2014 ……….…….... 190

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CO-AUTHORSHIP STATEMENT

This thesis consists of four chapters. Chapter One is an introduction to the work plan developed and proposed by the Canadian Mining Innovation Council (CMIC)- Footprints project committee. It includes a literature review and general descriptions of the geology for the two deposits analyzed, and is written by the author with editorial support of Dr. Piercey, supervisor of this thesis.

Chapter Two was written in collaboration with Dr. Piercey, Dr. Kevin Ansdell (University of Saskatchewan), Dr. Kurt Kyser (Queen’s University), Dr. Tom Kotzer and Gerard Zaluski (Cameco Corporation), and David Quirt (AREVA Resources Canada, Inc.).

All authors contributed significantly in both writing and interpretation of geochemical data.

Cameco Corporation provided all data, with laboratory work performed by Saskatchewan Research Council Geoanalytical Laboratories. Additional comments on the manuscript were provided by Dr. Stefanie Lode (Memorial University) and Dr. Jonathan Cloutier (University of St. Andrews). It is intended to be submitted to the journal GEEA after being reviewed by all sponsors of the CMIC-Footprints project per publication guidelines.

Chapter Three was written by the author with the supervision and editorial support of Dr. Piercey. Drs. Piercey, Ansdell, Kyser, Kotzer, and Mr. Zaluski were present for guidance and discussions during field work at the McArthur River deposit site, funded by Cameco Corporation. Additional comments on the manuscript were provided by Dr.

Jonathan Cloutier. All data was provided by Cameco Corporation, with laboratory work

performed by Saskatchewan Research Council Geoanalytical Laboratories. Written as a

stand-alone paper, it is intended to be submitted to a peer-reviewed journal after additional

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editorial support and collaboration by the co-authors of Chapter Two, and review by all sponsors of the CMIC-Footprints project per publication guidelines.

Chapter Four is a summary of the thesis, and includes suggestions for future work.

It, along with appendices A, B, and C, were written by the author with supervision and

editorial support from Dr. Piercey.

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CHAPTER 1: INTRODUCTION TO THE MILLENNIUM AND McARTHUR RIVER UNCONFORMITY-RELATED URANIUM DEPOSITS, ATHABASCA

BASIN, NORTHERN SASKATCHEWAN, CANADA

1.1 INTRODUCTION

Uranium is a critical resource for nuclear power generation. In nature, U consists of three radiogenic isotopes (

U,

U, and

U), only one of which,

U, is fissionable and necessary for energy production. The

U has a natural abundance of only 0.7%;

therefore, any minable ore is normally enriched as part of the mineral processing (Lehmann, 2008; Kyser, 2014) and any resource must have sufficient grade and tonnage for recovery to be economically feasible. Modern exploration for new prospects that meet these criteria is challenging and often requires a focus on mineralization that is deep and/or hidden below cover.

Unconformity-related U (URU) deposits are known for exceptional grades, making them especially desirable for recovery (Laverret et al., 2006). The preeminent location for these deposits is the Athabasca Basin, northern Saskatchewan and Alberta, Canada, one of the main sources of global uranium (Fig. 1.1; Kyser, 2014). Formation of URU deposits involves extensive hydrothermal fluid flow in a constrained location, and is a result of multiple factors including, but not limited to: timing, fluid chemistry, oxygen fugacity, pH, temperature, and rock composition (Hoeve and Sibbald, 1978; Hoeve and Quirt, 1984:

Fayek and Kyser, 1997). Accordingly, lithogeochemistry is particularly useful in

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exploration for such deposits because rock chemistry often reflects the above processes and provides vectors towards mineralization (Earle and Sopuck, 1989; Kyser et al., 2009).

During the hydrothermal alteration process, hydrothermal fluids leach U from source rocks and transport it, along with mobile elements such as Pb, Cu, Ni, Mo, B, V, and others, until it precipitates from the fluid due to geochemical and structural traps (Hoeve and Sibbald, 1978; Hoeve and Quirt, 1984; Jefferson et al., 2007; Cuney, 2009). Fluid-rock interaction during transport and deposition result in geochemical signatures reflective of ore forming processes. These become particularly enhanced in areas where the processes had been ongoing or occurred repeatedly over extended periods of time, or where fluid volumes were large (Earle and Sopuck, 1989; Kyser et al., 2000; Jackson, 2010). Commonly, clay mineral compositions (via hydrothermal alteration) and pathfinder elements (as redox-sensitive or U-associated arsenides and sulfides) associated with ore forming processes highlight these fluid pathways and can create vectors towards mineralization (Hoeve et al., 1981; Hoeve and Quirt, 1984).

Large-scale alteration haloes consisting of illite, chlorite, and dravite, and

anomalous Pb, Ni, Co, Cu, As, Mo, and B, are common vectors towards URU

mineralization (Sopuck et al., 1983; Hoeve and Quirt, 1984; Earle and Sopuck, 1989; Fayek

and Kyser 1997; Jefferson et al., 2007). Although there are no universal vectors that can be

applied to all URU deposits, the fluid-rock interactions associated with mineralization

processes result in common mineral and elemental associations (Tremblay, 1982; Earle and

Sopuck, 1989). This includes the alteration of the background mineral dickite to illite with

K-dominant fluids, with additional alteration forming chlorite and dravite with Mg-

dominant fluids (Earle and Sopuck, 1989). These anomalies are no guarantee of URU but

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instead are evidence of their potential though hydrothermal processes and the large fluid volumes necessary for deposit formation (Earle and Sopuck, 1989; Cloutier et al., 2010).

The later stages are indicative of fluids that can be basinal in origin or that have become enriched in Mg and B through fluid-rock interaction in the basement, the reduced nature of which is also necessary for the precipitation of U (Mercadier et al., 2012; Sheahan et al., 2016). Lead is a decay product of U; therefore, variable ratios of radiogenic Pb isotopes can be indicators of a concentrated source (mineralization), and their mobility in fluid events can leave signatures that can be used as vectors (Holk et al., 2003, Quirt, 2009).

Other trace elements (As, Co, Cu, Ni) are pathfinders or indicators as they are found in arsenides and sulfides associated with the formation of complex (polymineralic) U deposits (Hoeve and Sibbald, 1978; Tremblay, 1982). Because redox reactions are responsible for U precipitation, elements that are sensitive to these processes (Mo, V, Se, As, Cu) will be indicators as well (Kyser and Cuney, 2008; Kyser, 2014). Rare earth elements (REE) are also associated with URU deposits because their ionic radii is similar to that of U

, allowing for substitution in accessory minerals and REE-enrichment in uraninite (Shannon, 1976; Fayek and Kyser, 1997; Kyser, 2014).

The purpose of this thesis is to expand on these common exploration models by creating a detailed characterization of an extensive suite of major and trace elements, and clay mineral distribution, on a regional scale at two well-explored deposits. The Millennium and McArthur River deposits display differing mineralization styles (size, depth, and associated elements) despite their locations being within 50 km of each other and their spatial association with regional illite, chlorite, and dravite anomalies (Fig. 1.2a;

Earle and Sopuck, 1989; McGill et al., 1993; Roy et al., 2006). The lithogeochemical

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signatures of both deposits, each encompassing tens of kilometres, will be characterized for clay mineralogy and trace element haloes to determine any spatial relationships to mineralization. These features will be used to create scalable mineralogical and geochemical vectors towards mineralization.

1.2 UNCONFORMITY-RELATED URANIUM DEPOSITS

Unconformity-related uranium (URU) deposits are found at or near an unconformity between a Paleo- to Mesoproterozoic sedimentary basin and an Archean to Paleoproterozoic metasedimentary basement (Hoeve and Sibbald, 1978; Tremblay, 1982;

Hoeve and Quirt, 1984; Ruzicka, 1996; Cuney 2009; Kyser, 2014). These deposits are found mainly in Canada and Australia, and are often high grade, with several deposits containing greater than 1% U oxides (Ruzicka, 1996; Jefferson et al., 2007). Common elements for URU formation include 1) U-rich source rocks in the basin and basement; 2) an unconformity between basin and basement; 3) fractures or faults across the unconformity; 4) oxidized hydrothermal fluids to transport U interacting with a reductant to reduce the fluid and induce U precipitation at the site of deposition; and 5) forces to drive fluid movement (e.g., tectonics, gravity, density). The evolution in pH, temperature, oxygen fugacity, and salinity of the fluids are also critical to deposit formation (Kyser et al., 2009).

Precipitation of U is a consequence of a redox reaction, as U has two valence states:

U

(uranyl ion) and U

(uranous ion). The uranyl ion is easily soluble in oxidized, likely

basinally-derived hydrothermal fluids, and is transported until reduced and precipitated as

the uranous ion, usually as UO

(Langmuir, 1978; Romberger, 1985; Alexandre and Kyser

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2005; Cuney, 2009). The hydrothermal fluid-rock interaction responsible for mineralization begins with basinal brines extracting U from available detrital heavy minerals in the sandstones of the basin, such as zircon, monazite, and apatite (Hoeve and Sibbald, 1978; Hoeve and Quirt, 1984; Kyser, 2007; Fayek and Kyser, 1997), or from U sources in the basement such as pegmatites, granitoid rocks, and accessory monazite (Annesley et al., 2005; Hecht and Cuney, 2000). The reductant responsible for the precipitation reaction may be reduced fluids from the basement that mix with the oxidized fluids, or the reduced lithology of the basement itself (Hoeve and Sibbald, 1978; Tremblay, 1982; Hoeve and Quirt 1984). The location of the mineralization is dependent on the direction of syn- and post-ore fluid flows that result in precipitation at, above, or below the unconformity between the oxidized basin and reduced basement (Hoeve and Quirt, 1984;

Fayek and Kyser, 1997; Ruzicka, 1996; Jefferson et al., 2007).

In addition to oxidized fluids and reductants at the site of deposition, tectonic controls were also critical for converging fluid pathways and driving their movement (e.g., Tremblay, 1982; Ruzicka, 1996). Tectonic stresses created conduits (i.e., fractures and faults) for pathways across the unconformity to focus fluids, and, coupled with gravity, induced fluid flow in and out of the basement and basin (Tremblay, 1982; Cui et al., 2012).

Rheological contrast associated with reverse faulting also created necessary voids for fluid

transport and deposit formation (Annesley et al., 2005; Kerr and Wallis, 2014). This

focussing of fluid flow within a compact network of open fractures controlled both the

hydrothermal alteration of country rock and the precipitation of U (Raffensperger and

Garven, 1995; Kyser et al., 2000; Alexandre et al., 2009).

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Early genetic models for URU formation (Fig. 1.3a–b) were framed as two endmembers — defined by emplacement of mineralization at the unconformity (sandstone- hosted) or below (basement-hosted) — and interpreted to have resulted from fluid flow out of (egress) or into (ingress) the basement, respectively. Mineralization style (poly- or monomineralic) has also been correlated to location above and below the unconformity, respectively (Hoeve and Quirt, 1984; Fayek and Kyser 1997; Jefferson et al., 2007).

Subsequent models were based on the source of U: the basin, basement, or both (Ruzicka, 1996; Cuney et al., 2003; Kyser et al., 2000), and whether the reductant was basement- derived fluids or basement lithology (Hoeve and Sibbald, 1978; Hoeve and Quirt 1984;

Wilson and Kyser, 1987; Kotzer and Kyser 1995; Komninou and Sverjensky 1995; Fayek and Kyser, 1997). The large diversity of URU deposits with shared characteristics suggests that subtleties exist between model endmembers in terms of their genesis via multiple fluid events (Fig. 1.3c; Mercadier et al., 2012; Sheahan et al., 2016).

The two deposits studied herein are broadly defined as sandstone-hosted (McArthur

River) and basement-hosted (Millennium); however, each contain mineralization both at

and below the unconformity (McGill et al., 1993; Roy et al., 2006). The majority of the

Millennium deposit comprises monomineralic-style mineralization up to 150 m below the

unconformity, yet a considerable amount (up to 20%, G. Zaluski, pers. comm. 2015) occurs

at the unconformity. McArthur River comprises several mineralized pods, also

monomineralic, which occur in multiple ore zones mainly at but also below the

unconformity (McGill et al., 1993; Bronkhorst et al., 2012). Both deposits are situated

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along major reverse faults that are part of regional fault systems containing abundant graphite (Cloutier et al., 2009; Ng et al., 2013).

1.3 REGIONAL GEOLOGY 1.3.1 Basement

The Rae and Hearne provinces and the Taltson Magmatic Zone of the Canadian Shield Province compose the 2.9–1.8 Ga basement rocks beneath the Athabasca Basin (Fig.

1.1). The Rae and Hearne provinces collided along the Snowbird Tectonic Zone (1.92–1.89 Ga), followed by the accretion of the Paleoproterozoic Reindeer Zone rocks to the eastern margin of the Hearne Province during the Trans-Hudson Orogeny (THO) (Hoffman, 1988;

Ansdell, 2005; Corrigan et al., 2009).

The Rae Province underlies the western half of the Athabasca Basin and the Hearne

Province the eastern half; URU deposits are associated with both provinces. The

Millennium and McArthur River deposits are located in the southeastern part of the basin,

where it overlies the Mudjatik and Wollaston domains of the Hearne Province (Lewry and

Sibbald 1980; Hoffman, 1988; Ruzicka, 1996; Jefferson et al., 2007). The Mudjatik

Domain is to the west of the Wollaston Domain, and consists of mainly Archean granitoid

gneisses with scattered Archean and Paleoproterozoic supracrustal rocks; the Wollaston

Domain contains Archean granitoid gneisses with overlying Paleoproterozoic

metasedimentary rocks (Annesley et al. 2005; Yeo and Delaney, 2007). Unconformity-

related U deposits in the southeastern Athabasca Basin are clustered in a region within or

near the transition between the Wollaston and Mudjatik domains, an area approximately

8

20 km wide, known as the Wollaston-Mudjatik Transition Zone (WMTZ) (Fig. 1.2a;

Annesley et al., 2005; Jeanneret et al., 2016).

Far-field tectonic activity affected the Rae and Hearne provinces after their amalgamation, reactivating faults and fractures via both extensional and compressional tectonics, which created the space and differential permeability necessary for fluid movement into and out of the basement (Hoeve and Quirt 1984; Alexandre and Kyser, 2005; Boiron et al., 2010; Sheahan et al., 2016). Regional graphite-bearing fault systems are common first order URU exploration targets via electromagnetic techniques.

Traditionally, graphite has been an exploration target due to its empirical association with URU deposits after the Key Lake discovery, leading to the hypothesis of the reducing capabilities of the related alteration product, methane; however, current research suggests that U is capable of precipitating with or without its presence (Raffensperger and Garven, 1995; Aghbelagh and Yang, 2014). Instead, the association of graphite with U deposits likely reflects its presence in reactivated faults, creating high permeability conduits for focussing long-term fluid flow between the basin and basement (Aghbelagh and Yang, 2014; Kerr and Wallis, 2014). Other potential reductants for the formation of UO

are Fe

and H

S from the alteration of pyrite, or Fe

produced by the chlorite alteration of biotite, both of which are present in the metasedimentary rocks beneath the Athabasca Basin (Yeo and Potter, 2010).

1.3.2 Athabasca Basin

The Athabasca Basin is a basin of quartzose sandstone fill that lies unconformably

over the regolith developed atop the Rae and Hearne province basement rocks (Kyser,

9

2014). Initiation of sedimentation in the Athabasca Basin is suggested to be about 1.75–

1.73 Ga based on timing of the Trans-Hudson uplifts (Kyser et al., 2000; Ramaekers and Catuneanu, 2004). An age of 1.74–1.73 Ga has also been proposed by Rainbird et al.

(2007), with a 10–20 Ma gap between the end of the THO and the thermal subsidence of the basin, accounting for the difference in orientation between the NE-SW trend of the THO and the E-W geometry of the basin. An age of 1.7–1.65 Ga was suggested by Cumming and Krstic (1992) from U-Pb dating of diagenetic fluorapatite assumed to be representative of the minimum age of deposition.

Three subbasins are found within the Athabasca; from west to east they are the Jackfish (oldest), Mirror (largest and youngest) and Cree. The Cree hosts the Millennium and McArthur River deposits, as well as the majority of URU deposits (Hiatt and Kyser, 2007). The basin contains four sequences comprising a total of eight formations, most of which are interpreted to have been deposited in a fluvial environment (Ramaekers and Catuneanu, 2004). Formations generally exhibit basal, thin, coarsening-upwards beds overlain by a series of fining-upwards sandstones. Ramaekers and Catuneanu (2004) suggested these coarse beds to be a result of a low accommodation systems tract filled in by prograding fluvial deposits; once level, fining up sequences continued deposition as part of a high accommodation systems tract.

The basin is intracratonic with no evidence of rift-related activity (Hiatt and Kyser, 2007). Based on paleomagnetic data, Kotzer et al. (1992) determined that diagenesis within the Athabasca occurred in three distinct time periods: 1.75–1.6 Ga (initial diagenesis), 1.6–

1.45 Ga (peak diagenesis), and 0.9 Ga (thermal alteration), concluding that fluid flow was

10

episodic and basin-wide. After 1.65 Ga, tectonic activity associated with multiple far-field events caused the creation/reactivation of faults and fractures, along with basin tilting, which induced fluid flow along with free thermal convection (Hoeve and Quirt, 1984;

Richard et al., 2010; Chi et al., 2013). Uranium-Pb ages on U minerals support the interpretation that punctuated fluid flow events in the Athabasca Basin were responsible for episodes of mineralization; these events coincided with the Wyoming and Mazatzal orogenies (1.6–1.5 Ga), Berthoud Orogeny (1.4 Ga), Mackenzie Dike Swarm (1.3 Ga), Grenville Orogeny (1.1–1.0 Ga), and the breakup of Rodinia (0.8 Ga) (Fayek et al., 2002;

Alexandre et al., 2009). During these events, the coincidence of tectonic driven fluid flow, appropriate sedimentary facies with adequate permeability and porosity, structural conduits to focus fluid flow, and suitable physical and chemical traps led to the formation and remobilization of world class U mineralization (Alexandre et al., 2009).

1.4 DEPOSIT GEOLOGY

1.4.1 Wollaston-Mudjatik Transition Zone (Hearne Province)

The Wollaston-Mudjatik Transition Zone (WMTZ), located in the Hearne

Province, is a ~20 km wide corridor between the Wollaston and Mudjatik domains that

hosts, or is proximal to, many URU deposits in the southeastern Athabasca Basin

(Annesley et al., 2005; Jeanneret et al., 2016), including the Millennium and McArthur

River deposits (Fig. 1.2a). The rheological contrast and repeated transpressional faulting

between the Wollaston and Mudjatik domains resulted in available space for U-bearing

intrusions such as leucogranites and pegmatites to form, and pathways for fluid to enter

and exit the basement (Annesley et al., 2005). The U-enrichment of the leucogranites and

11

pegmatites is interpreted to be due to partial melting of the metasedimentary rocks during the end of the THO (1.8 Ga) (Mercadier et al., 2013; Jeanneret et al., 2016). The WMTZ is also located within a high-heat production corridor that may have caused crustal melting, providing unusually high (2–5% by weight) U content in monazites (Annesley et al., 2005).

Structural reactivation in the WMTZ, in combination with a U-rich lithologies, created an ideal environment for URU deposit formation (Jeanneret et al., 2016).

1.4.2 B1 and P2 trends

Both the Millennium and the McArthur River deposits are situated on and in major reverse faults near the WMTZ (McGill et al., 1993; Roy et al., 2006). These faults are part of graphitic structural trends that strike NNE, known as the B1 and P2 trends, respectively;

they are within 15 km of each other but are not directly connected (Fig. 1.2b).

The B1 basement trend hosts the Millennium deposit, where mineralization is mainly situated between two dominant reverse faults (Fig. 1.4). The lower, footwall fault is known as the ‘Mother’ fault and the upper, hanging wall fault has no formal name; both probably controlled fluid flow (Roy et al., 2006; Cloutier et al., 2009; Fayek et al., 2010).

The basement rocks are deformed and extensively altered, exhibiting distal saussurite and

sericite alteration and chlorite, dravite, and argillic alteration proximal to mineralization

(Fig. 1.4b). The footwall lithologies have not been fully explored (Roy et al., 2006). The

hanging wall lithologies above the Mother fault include calc-silicates, pelitic to semipelitic

gneisses and schists, graphitic pelitic schists, pegmatites and leucogranites (Roy et al.,

2006; Cloutier et al., 2009). Near the upper reverse fault is the Marker Unit, which hosts

12

ore-grade mineralization and contains graphitic metasedimentary rocks, as well as cordierite porphyroblastic pelitic schist (Roy et al., 2006).

The P2 trend, generally trending 045° in its entirety, hosts the McArthur River deposits (McGill et al., 1993; Ng et al., 2013). The P2 trend reverse fault displaces the hanging wall by 60–80 m, within Wollaston Domain basement rocks rich in graphite, through multiple fault zones dipping 40°–65° SE (McGill et al., 1993; Bronkhorst et al., 2012). These basement rocks consist of metasedimentary units, as in the B1 trend mentioned above. The hanging wall is predominantly pelitic and psammopelitic gneisses containing cordierite and graphite; the footwall is dominantly calc-silicate and quartzite units (McGill et al., 1993). Alteration minerals in the basement rocks include illite, chlorite, and dravite, with chlorite dominant proximal to the orebody, and illite dominant at more distal locations (Alexandre et al., 2005). Mineralization is hosted above, at, and below the unconformity in different zones within the P2 trend. Zones 1–4 South and A–C are collectively considered the McArthur River deposit, formerly known as P2 North (Fig. 1.5;

Bronkhorst et al., 2012). There is a currently subeconomic mineralized zone at the southwestern end of the study area, not part of the McArthur River deposit, known as P2 Main (Bronkhorst et al., 2012). Figure 1.2b illustrates the trends and deposit locations for both the Millennium and McArthur River study areas.

1.4.3 Manitou Falls Formation

Fluid inclusion and clay mineralogy studies suggest that the Athabasca Basin was

once 5–6 km deep; since its formation, erosion has reduced its overall sediment thickness

to 1–2 km (Pagel et al., 1980; Hoeve et al., 1981). In the southeastern area of the basin

13

hosting the study areas, the depth of sedimentary cover over the Millennium and McArthur River deposits is 500–750 m and 480–560 m, respectively (Roy et al., 2006; McGill et al., 1993).

The Millennium and McArthur River deposits are both overlain by the Manitou Falls Formation (Ramaekers and Catuneanu, 2004). The Manitou Falls Formation comprises sublithic arkose to quartz arenite with 90–95% SiO

on average (Quirt 1985;

Hiatt and Kyser, 2007), and is unmetamorphosed and generally flat-lying (McGill et al.,

1993; Hiatt and Kyser, 2007). It is divided into four lithofacies, the upper three being

products of a braided fluvial depositional environment and the stratigraphically lowest

sourced from both a braided fluvial and an alluvial fan environment (Hiatt and Kyser,

2007). From oldest to youngest, they are MFa (at the unconformity), overlain by MFb,

MFc, and uppermost MFd, which is overlain by up to 100 m of overburden (Campbell,

2007). In some areas, the base of the MFa corresponds to the unconformity itself; in others,

the MFa is in contact with a fanglomerate, which is above the unconformable contact

(McGill et al., 1993; Quirt, 2000). The fanglomerate is more prevalent at McArthur River

than at Millennium, averaging 10 m thick over the hanging wall unconformity and 25 m

thick over the footwall unconformity, and consists of clasts of Paleoproterozoic quartzite

(McGill et al., 1993). Ramaekers et al. (2007) renamed the Manitou Falls Formation

lithofacies; in particular, the MFa to the Read Formation as a method to redefine the basal

lithofacies and their relationship to the unconformity. However, as all samples collected

for this study are classified as being from one of the A–D Manitou Falls Formation

14

lithofacies, the original nomenclature is retained in this thesis. These individual lithofacies are described in greater detail in Chapters 2 and 3.

Large-scale alteration halos containing clay-type minerals (illite, chlorite, and dravite) often associated with URU deposits are abundant in the Manitou Falls Formation at all depths (Earle and Sopuck, 1989; Kotzer and Kyser, 1995). They extend for 10s of kilometres and illustrate the extent of diagenetic and hydrothermal processes, accompanied by bleaching (Hoeve and Quirt, 1984; Zhang et al., 2001; Jefferson et al., 2007). The stratigraphy and lithofacies of the Manitou Falls Formation controlled the lateral movement of diagenetic and hydrothermal fluids (Kotzer and Kyser, 1995). This is supported by the interpretation of a diagenetic aquitard in limited locations of the eastern Athabasca between the MFb and MFa lithofacies (Hiatt and Kyser, 2007), and the uranogenic Pb isotope signatures recognized to extend 100s of metres laterally within the MFa (Holk et al., 2003).

Consequently, lithostratigraphic variation, along with diagenetic or hydrothermal sealing processes, were important factors in controlling the direction of fluid flow, quartz cementation, and ultimately the location of mineralization (Hoeve and Quirt, 1984; Hiatt and Kyser, 2007; Ng et al., 2013).

1.5 THESIS OBJECTIVES

The main goal of the project was to develop a 3D lithogeochemical footprint of two

URU deposits. Both the Millennium and McArthur River deposits are associated with

major reverse faults with evidence of past hydrothermal fluid-rock interaction, which left

variable mineralogical and geochemical signatures at varying distances from

mineralization, at multiple stratigraphic levels. Major elements associated with alteration

15

minerals (Al, Mg, K) are known to form large-scale (100s of metres) haloes associated with URU deposits (Earle and Sopuck, 1989; Zhang et al., 2001; Laverret et al., 2006; Jefferson et al., 2007). Trace elements related both to U mineralization (e.g., Pb, Co, Ni, As) and other redox active elements (e.g., Mo, V) occur in elevated amounts in and around URU deposits as well, albeit on a smaller scale (Hoeve and Sibbald, 1978; Tremblay, 1982; Ng et al., 2013). The distributions of these traditional pathfinder elements are well documented around the edges of U mineralization; however, less understood are the distal edges of the related alteration haloes and how they can be utilized for vectoring purposes. Abundant legacy data were provided to the author by Cameco Corporation to define the edges of these alteration patterns surrounding the Millennium and McArthur River deposits. Nearly three decades of exploration, including over 10,000 individual sample analyses, facilitated large study areas (~20 km strike length at both locations) that illustrate the alteration footprint on a district scale that has never been fully interrogated before. This results in a more comprehensive footprint than those from smaller or more targeted datasets. By focussing on the distal edges of the sandstone alteration, a set of criteria can be developed to aid in future exploration efforts. In doing so, the following questions were addressed:

1) What elemental concentrations define the distal edges of alteration related to mineralization processes, and what are the halo dimensions?

2) Are there elements or a combination of elements that may be useful as pathfinders to vector toward U mineralization?

The data summarized in this thesis will be integrated with other researchers’ work

as part of the major data integration initiative in the Canadian Mining Innovation Council

16

(CMIC)-Footprints project to develop a comprehensive integrated geological, geochemical, mineralogical, and geophysical footprint of the U deposits in the Athabasca Basin.

1.6 METHODS

1.6.1 Whole rock geochemistry: legacy database

The footprint areas for the Millennium and McArthur River deposits have been actively drilled since 1987 and 1984, respectively, creating a legacy database of whole rock geochemical results of over 10,000 samples. These representative (composite) Manitou Falls Formation samples were composed of a series of sandstone chips ~1 cm thick, collected approximately every 1.5 m over intervals of 5, 10, or 20 m, and logged as belonging to a specific lithofacies. Fanglomerate samples were excluded from the data analysis as they are not consistently present throughout the study areas. Early exploration comprised the common pathfinder elements Cu, Ni, Pb, B, and U, which were analyzed using atomic absorption spectrophotometry (AAS) and inductively coupled plasma optical emission spectrometry (ICP-OES) (Quirt, 1985). Later analyses included a greater breadth of major and trace elements, increased accuracy, and lower detection limits with the addition of inductively coupled plasma mass spectrometry (ICP-MS). Saskatchewan Research Council (SRC) Geoanalytical Laboratories performed all whole rock

geochemistry, utilizing partial (2-acid) and total (3-acid) digestion methods. Their

methodology is described in detail in Chapter 2. Appendix A describes how the data was

selected and filtered, for both deposits, with respect to differences in sample collection

17

and accuracy and precision variations over time. Table A.1 shows the most current analysis suite, including instrumentation used and detection limits for each element.

This database was provided to the author for interpretation. Samples were restricted to those that contained ≤1000 ppm U (total and partial digestion) to focus on the distal geochemical signature not significantly influenced by ore bodies. This legacy data for both the Millennium and McArthur River deposits provide the basis for the bulk of the lithogeochemical and spatial analysis in this thesis, as discussed in Chapters 2, 3, and 4.

1.6.2 Drill core sample collection: new data

New data was also obtained on samples collected from McArthur River deposit

drill cores in July–August 2014 to augment the historical data through targeted sample

collection related to the McArthur River deposit. A total of 230 sandstone grab samples

from 13 cores across four fences (sections) were collected, to include sandstone above and

adjacent to areas with high, low, and negligible mineralization, from near surface to the

unconformity. Individual samples were split lengthwise at Memorial University, and

shared between the author and collaborator Nicholas Joyce (M.Sc. candidate, Queen’s

University), who focussed on mineralogy, mineral chemistry, and quantitative mineral

analysis of the same samples. Adjacent samples were collected for petrophysical analysis

by other researchers as part of the data integration initiative of the CMIC-Footprints

Project. Of the split samples, the author cut specimens for whole rock geochemistry that

were analyzed at SRC Laboratories (ICP-MS1 analysis suite), with the specific addition of

SiO

and B analyses. Additionally, 58 thin section specimens were cut and prepared by

Vancouver Petrographic Laboratories. Sample collection and results are summarized in

18

Chapter 3. Appendices D and E contain the sample locations and whole rock geochemical (new data only) results.

1.6.3 Short-wave infrared spectroscopy

Short-wave infrared spectroscopy (SWIR) is an instrumental spectral analysis performed directly on drill core without further sample preparation (Russell and Fraser, 1994; Percival et al., 2002). Cameco’s portable instrumentation (PIMA II or ASD Terraspec instruments, with MinSpec 4 software) analyzes for 5 minerals: kaolinite, dickite, illite, dravite, and chlorite. The methodology is described in greater detail in Appendix B. As it is inexpensive and can be done immediately upon core retrieval, the analysis for alteration-related mineralogy is a quick and simple way to identify diagenetic and hydrothermal (both K-related (illite); and Mg-related (chlorite, dravite)) alteration for large-scale vectoring. Cameco provided legacy SWIR data to the author, and SWIR determination on the new samples collected in 2014 was completed at Queen’s University.

Results for both deposits are summarized in Chapter 4 and Appendix B.

1.6.4 Results: 3D analysis and statistics

3D spatial analysis is a visual medium for projecting the lithogeochemical analyses

mentioned above in relation to the deposit location. For this thesis, Geosoft® Target

version 4.5.5., an add-on to ArcGIS geospatial software, was utilized to add dimensionality

to the analysis through the projection of theoretical results between sample locations via

inverse-distance weighting algorithms. It was also used to measure the large-scale

approximate haloes of geochemical anomalies. All mathematical analysis and graphs

utilized SPSS, an IBM-based statistical software program.

19 1.7 PRESENTATION

This thesis consists of three chapters and four appendices. Chapter 1 is an introduction to unconformity-related U deposits, and the geology associated with the Millennium and McArthur River deposits that are the focus of this study. Chapter 2 is a manuscript presenting the lithogeochemical footprint and the shallow vectoring possibilities of whole rock geochemistry for the Millennium deposit, and is intended for publication in a scientific, peer-reviewed journal. Chapter 3 summarizes the distal lithogeochemical signature of the McArthur deposit and the use of molar element ratios as vectors, and is also intended for eventual publication in a scientific, peer-reviewed journal.

Chapter 4 summarizes the similarities and differences between the McArthur and Millennium lithogeochemical footprints. The Appendices include summaries of the data leveling process, SWIR results from the Millennium and McArthur River deposits, preliminary scanning electron microscope work on the thin sections from McArthur River samples collected, and the whole rock geochemical results on the samples collected at the McArthur River deposit.

REFERENCES

Aghbelagh, Y. B., & Yang, J. (2014). Effect of graphite zone in the formation of unconformity-related uranium deposits: Insights from reactive mass transport modeling. Journal of Geochemical Exploration, 144(PA), 12–27.

http://doi.org/10.1016/j.gexplo.2014.01.020

Alexandre, P., & Kyser, K. (2005). Effect of cation substitutions and alteration of uraninite. Canadian Mineralogist, 45, 1005–1017.

http://doi.org/10.2113/gscanmin.43.3.1005

20

Alexandre, P., Kyser, K., Polito, P., & Thomas, D. (2005). Alteration mineralogy and stable isotope geochemistry of Paleoproterozoic basement-hosted unconformity- type uranium deposits in the Athabasca Basin, Canada. Economic Geology, 100(8), 1547–1563. http://doi.org/10.2113/gsecongeo.100.8.1547

Alexandre, P., Kyser, K., Thomas, D., Polito, P., & Marlat, J. (2009). Geochronology of unconformity-related uranium deposits in the Athabasca Basin, Saskatchewan, Canada and their integration in the evolution of the basin. Mineralium Deposita, 44(1), 41–59. http://doi.org/10.1007/s00126-007-0153-3

Annesley, I. R., Madore, C., & Portella, P. (2005). Geology and thermotectonic evolution of the western margin of the Trans-Hudson Orogen: evidence from the eastern sub- Athabasca basement, Saskatchewan. Canadian Journal of Earth Sciences, 42(4), 573–597. http://doi.org/10.1139/e05-034

Ansdell, K. M. (2005). Tectonic evolution of the Manitoba-Saskatchewan segment of the Paleoproterozoic Trans-Hudson Orogen, Canada. Canadian Journal of Earth Sciences, 42(4), 741–759. http://doi.org/10.1139/e05-035

Beaufort, D., Cassagnabere, A., Petit, S., Lanson, B., Berger, G., Lacharpagne, J. C., &

Johansen, H. (1998). Kaolinite-to-dickite reaction in sandstone reservoirs. Clay Minerals, 33(2), 297–316.

Boiron, M. C., Cathelineau, M., & Richard, A. (2010). Fluid flows and metal deposition near basement/cover unconformity: lessons and analogies from Pb–Zn–F–Ba systems for the understanding of Proterozoic U deposits. Geofluids, 10(1‐2), 270–

292. http://doi.org/10.1111/j.1468-8123.2010.00289.x

Bronkhorst, D., Edwards, C. R., Mainville, A. G., Murdock, G. M., & Yesnik, L. D.

(2012). McArthur River operation, northern Saskatchewan, Canada. National Instrument 43-101 Technical Report: Cameco Corporation, 206 p.

Campbell, J. E. (2007). Quaternary geology of the eastern Athabasca Basin,

Saskatchewan. In Jefferson C. W. & Delaney, G. (eds.), EXTECH IV: Geology and Uranium EXploration TECHnology of the Proterozoic Athabasca Basin,

Saskatchewan and Alberta: Geological Survey of Canada, Bulletin 588, 211–228.

Card, C. D., Panǎ, D., Portella, P., Thomas, D. J., & Annesley, I. R. (2007). Basement rocks to the Athabasca basin, Saskatchewan and Alberta. In Jefferson C. W. &

Delaney, G. (eds.), EXTECH IV: Geology and Uranium EXploration TECHnology of the Proterozoic Athabasca Basin, Saskatchewan and Alberta: Geological Survey of Canada, Bulletin 588, 69–87.

Chi, G., Bosman, S., & Card, C. (2013). Numerical modeling of fluid pressure regime in the Athabasca basin and implications for fluid flow models related to the

unconformity-type uranium mineralization. Journal of Geochemical

21

Exploration, 125, 8–19. http://doi.org/10.1016/j.gexplo.2012.10.017 Cloutier, J., Kyser, K., Olivo, G. R., Alexandre, P., & Halaburda, J. (2009). The

Millennium uranium deposit, Athabasca Basin, Saskatchewan, Canada: an atypical basement-hosted unconformity-related uranium deposit. Economic Geology, 104(6), 815–840. http://doi.org/10.2113/gsecongeo.104.6.815

Cloutier, J., Kyser, K., Olivo, G. R., & Alexandre, P. (2010). Contrasting patterns of alteration at the Wheeler River area, Athabasca basin, Saskatchewan, Canada:

insights into the apparently uranium-barren zone K alteration system. Economic Geology, 105(2), 303–324. http://doi.org/10.2113/gsecongeo.105.2.303

Corrigan, D., Pehrsson, S., Wodicka, N., & de Kemp, E. (2009). The Palaeoproterozoic Trans-Hudson Orogen: a prototype of modern accretionary processes. Geological Society, London, Special Publications, 327(1), 457–479.

http://doi.org/10.1144/SP327.19

Cui, T., Yang, J., & Samson, I. M. (2012). Tectonic deformation and fluid flow:

implications for the formation of unconformity-related uranium deposits. Economic Geology, 107(1), 147–163. http://doi.org/10.2113/econgeo.107.1.147

Cumming, G. L., & Krstic, D. (1992). The age of unconformity-related uranium

mineralization in the Athabasca Basin, northern Saskatchewan. Canadian Journal of Earth Sciences, 29(8), 1623–1639. http://doi.org/10.1139/e92-128

Cuney, M. (2009). The extreme diversity of uranium deposits. Mineralium Deposita, 44(1), 3–9. http://doi.org/10.1007/s00126-008-0223-1

Cuney, M., Brouand, M., Cathelineau, M., Derome, D., Freiberger, R., Hecht, L., Kister, P., Lobaev, V., Lorilleux, G., Peiffert, C., & Bastoul, A. M. (2003). What

parameters control the high grade-large tonnage of the Proterozoic unconformity related uranium deposits? In Cuney, M. (ed.), Proceedings of the International Conference on Uranium Geochemistry: Nancy, France, p. 123–126.

Earle, S. A. M., & Sopuck, V. J. (1989). Regional lithogeochemistry of the eastern part of the Athabasca Basin uranium province, Saskatchewan, Canada. In Muller-Kahle, E., (ed.), Uranium resources and geology of North America: International Atomic Energy Agency, TECDOC-500, 263–296.

Fayek, M. & Kyser, T. (1997). Characterization of multiple fluid-flow events and rare- earth-element mobility associated with formation of unconformity-type uranium deposits in the Athabasca Basin, Saskatchewan. The Canadian Mineralogist, 35, 627–658.

Fayek, M., Kyser, T. K., & Riciputi, L. R. (2002). U and Pb isotope analysis of uranium

minerals by ion microprobe and the geochronology of the McArthur River and Sue

22

Zone uranium deposits, Saskatchewan, Canada. The Canadian Mineralogist, 40(6), 1553–1570.

Fayek, M., Camacho, A., Beshears, C., Jiricka, D., & Halaburda, J. (2010). Two Sources of Uranium at the Millennium Uranium Deposit, Athabasca Basin, Saskatchewan, Canada. In Geological Association of Canada—Mineralogical Association of Canada 2010 (Calgary) Annual Conference Abstracts Volume, 4 p.

Hecht, L., & Cuney, M. (2000). Hydrothermal alteration of monazite in the Precambrian crystalline basement of the Athabasca Basin (Saskatchewan, Canada): implications for the formation of unconformity-related uranium deposits. Mineralium Deposita, 35(8), 791–795. http://doi.org/10.1007/s001260050280

Hiatt, E. E., & Kyser, T. K. (2007). Sequence stratigraphy, hydrostratigraphy, and mineralizing fluid flow in the Proterozoic Manitou Falls Formation, eastern

Athabasca Basin, Saskatchewan. In Jefferson C.W. & Delaney, G. (eds.), EXTECH IV: Geology and Uranium EXploration TECHnology of the Proterozoic Athabasca Basin, Saskatchewan and Alberta: Geological Survey of Canada, Bulletin 588, 489–506.

Hoeve, J., & Quirt, D. H. (1984). Mineralization and host rock alteration in relation to clay mineral diagenesis and evolution of the Middle-Proterozoic, Athabasca Basin, northern Saskatchewan, Canada. Saskatchewan Research Council, SRC Technical Report 187, 202 p.

Hoeve, J., & Sibbald, T. I. (1978). On the genesis of Rabbit Lake and other

unconformity-type uranium deposits in northern Saskatchewan, Canada. Economic Geology, 73, 1450–1473.

Hoeve, J., Rawsthorn, K., & Quirt, D. (1981). Uranium metallogenetic studies: clay mineral stratigraphy and diagenesis in the Athabasca Group. In Summary of

Investigations 1981, Saskatchewan Geological Survey, Miscellaneous Report 81-4, p. 76–89.

Hoffman, P. F. (1988). United Plates of America, the birth of a craton: Early Proterozoic assembly and growth of Laurentia. Annual Review of Earth and Planetary

Sciences, 16, 543–603.

Holk, G. J., Kyser, T. K., Chipley, D., Hiatt, E. E., & Marlatt, J. (2003). Mobile Pb- isotopes in Proterozoic sedimentary basins as guides for exploration of uranium deposits. Journal of Geochemical Exploration, 80(2), 297–320.

http://doi.org/10.1016/S0375-6742(03)00196-1

Jackson, R. G. (2010). Application of 3D geochemistry to mineral exploration.

Geochemistry: Exploration, Environment, Analysis, 10(2), 143–156.

http://doi.org/10.1144/1467-7873/09-217

23

Jeanneret, P., Goncalves, P., Durand, C., Trap, P., Marquer, D., Quirt, D., & Ledru, P.

(2016). Tectono-metamorphic evolution of the pre-Athabasca basement within the Wollaston–Mudjatik Transition Zone, Saskatchewan. Canadian Journal of Earth Sciences, 53(3), 231–259. http://doi.org/10.1139/cjes-2015-0136

Jefferson, C. W., Thomas, T. J., Gandhi, S. S., Ramaekers, P., Delaney, G., Brisbin, D., Cutts, C., Portella, P., & Olson, R.A. (2007). Unconformity-associated uranium deposits of the Athabasca Basin, Saskatchewan and Alberta. In Jefferson C. W. &

Delaney, G. (eds.), EXTECH IV: Geology and Uranium EXploration TECHnology of the Proterozoic Athabasca Basin, Saskatchewan and Alberta: Geological Survey of Canada, Bulletin 588, 23–67.

Kerr, W. & Wallis, R. (2014). “Real-world” economics of the uranium deposits of the Athabasca Basin, northern Saskatchewan: why grade is not always king! SEG Newsletter, (99) 1, 11–15.

Komninou, A., & Sverjensky, D. A. (1995). Hydrothermal alteration and the chemistry of ore-forming fluids in an unconformity-type uranium deposit. Geochimica et

Cosmochimica Acta, 59(13), 2709–2723. http://doi.org/10.1016/0016- 7037(95)00167-X

Kotzer, T. G., & Kyser, T. K. (1995). Petrogenesis of the Proterozoic Athabasca Basin, northern Saskatchewan, Canada, and its relation to diagenesis, hydrothermal

uranium mineralization and paleohydrogeology. Chemical Geology, 120(1), 45–89.

http://doi.org/10.1016/0009-2541(94)00114-N

Kotzer, T. G; Kyser, T. K.; Irving, E. (1992) Paleomagnetism and the evolution of fluids in the Proterozoic Athabasca Basin, northern Saskatchewan, Canada. Canadian Journal of Earth Sciences 29(7), 1474–1491. http://doi.org/10.1139/e92-118 Kyser, T. K. (2007). Fluids, basin analysis, and mineral deposits. Geofluids, 7(2), 238–

257. http://doi.org/10.1111/j.1468-8123.2007.00178.x

Kyser, K. (2014). Uranium Ore Deposits, In Turekian, H. D., Holland, H. D., (eds.), Treatise on Geochemistry (2nd ed.): Oxford, Elsevier, v. 7, p. 489–513.

http://doi.org/10.1016/B978-0-08-095975-7.01122-0

Kyser, K., & Cuney, M. (2008). Unconformity-related uranium deposits. In Cuney, M. &

Kyser, K., (eds.), Recent and not-so-recent developments in uranium deposits and implications for exploration. Quebec: Mineralogical Association of Canada Short Course Series Vol. 39, 161–219. ISBN 978-0-921294-48-1

Kyser, K., Hiatt, E., Renac, C., Durocher, K., Holk, G., & Deckart, K. (2000). Diagenetic fluids in Paleo-and Meso-Proterozoic sedimentary basins and their implications for long protracted fluid histories. In Kyser, K. (ed.), Fluids and basin evolution.

Mineralogical Association of Canada Short Course Series 28: 225–262.